<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>flex-item</title>
    <style>

        .container{
            display: flex;
            flex-direction: row;
            align-items: center;

            width: 400px;
            height: 400px;
            background-color: gray;
        }


        .item{
            width: 60px;
            height: 60px;
           border: 1px solid;
        }

        .item1{
            order: 10;
            flex-grow: 10;
            align-self: flex-start;
        }


        .item2,.item3{
            order: 1;
        }
    </style>
</head>
<body>

<div class="container">

    <div class="item item1">1</div>
    <div class="item item2">2</div>
    <div class="item item3">3</div>

</div>
</body>
</html>